With rapid development of the display technology, touch screen panels have been gradually and widely applied in people's lives. Currently, according to the structures, the touch screen panels may be divided into: add-on touch panels, on-cell touch panels and in-cell touch panels. For example, an add-on touch panel is manufactured by separately producing a touch screen and a display which are then bonded together to form a display device with a touch function. The add-on touch panel has defects such as a high production cost, a low light transmittance, thick modules, etc. An in-cell touch panel is to embed touch electrodes of a touch screen into a display, which not only can reduce an overall thickness of modules but also can greatly reduce a production cost of the touch panel. The in-cell touch panel is favored by various panel manufacturers. In the technology of the in-cell touch panel, mutual-capacitive touch panels have become a mainstream in the technical development of the current in-cell touch panels due to advantages such as high sensitivity and multi-point touch.
More specifically, an in-cell touch panel is a device in which touch scanning lines and touch sensing lines in a touch screen are integrated into a display screen. For instance, the touch scanning lines and the touch sensing lines are integrated into a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display. In a traditional design, as shown in FIG. 1, touch scanning signals on touch scanning lines Txn (n=1, 2, 3 . . . ) are transmitted by an external driver (integrated circuit (IC)) through wirings disposed at a border area. However, with an increased size of the display device, the number of the touch scanning lines Txn is increased, so that the number of the wirings for transmitting the touch scanning signals to the touch scanning lines Txn is also correspondingly increased. Thus, a space occupied by the wirings can be increased, and hence the application of the in-cell technology in large-size and narrow-bezel display devices can be limited.
In order to solve the above problems, a touch driving circuit for outputting touch scanning signals to touch scanning lines is generally integrated on an array substrate currently, so that the wirings at the border area can be saved, and hence the narrow-bezel design of large-size displays can be achieved. Therefore, a touch driving circuit integrated on an array substrate has become a technical problem that is needed to be solved in the field.